The present invention relates generally to speech recognition and more particularly to contextual speech recognition.
As technology has advanced from the controlled areas in which only technical users interface with machines to the office and home use, it has become increasingly important to develop a friendly interface between man and machine. Speech synthesis has provided ease of communicating from the machine to the man in a friendly manner. It has remained difficult, or impossible, for the man to operate in a natural human language and have proper machine recognition.
Typically, speech recognition isolates particular words which may be recognized. This repertoire of recognition is almost universally limited to a few words which the machine is capable of understanding. As the repertoire of the machine is limited, so is its applicability to many situations. The user upon attempting to interface with the machine, when he finds it unable to understand the spoken word, is frustrated and tends to avoid interaction with the machine. This alienation of the user prevents the electronic apparatus from properly providing the aid and assistance for which it was designed.
Recognition of the meaning of spoken words has remained a perplexing problem due to cultural, geographic, and physical differences between speakers. A good tutorial article on speech recognition is "Isolated and Connected Word Recognition-Theory and Selected Applications" by Lawrence Rabiner and Stephen E. Levinson in IEEE Trans. Comm., Vol Com-29, No. 5, May 1981, pages 621-659. The Rabiner et al article though remains in the theoretical stage and does not allow for the meaning of words to flow past the recognition stage.
The necessity to go to a limited repertoire has been created in part by an inability on the part of technology to be fully comfortable with the myriad of variations available in the human language. Besides the variations available, many thoughts are communicated which are literal translations; or, similar words or homonyms tend to confuse the electronic apparatus.
Word for word translation alone is insufficient to provide proper interfacing.